青藏高原东部兴措湖生物壳体元素及同位素记录的气候环境信息  

Climatic Signals Recorded in Stable Isotope and Trace Elements of Shells in Xincuo Lake, Eastern Tibetan Plateau

作　　者：吴敬禄[1] G.H.Schleser 夏威岚[1] Andreas Lcke 李世杰[1] 王苏民[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所 [2]Forschungszentrum Jlich,D-52425 Jlich,Germany

出　　处：《湖泊科学》2001年第3期220-226,共7页Journal of Lake Sciences

基　　金：国家自然科学基金 ( 4 980 3 0 0 1);国家重点基础研究发展规划项目 (G19980 4 0 80 0 )联合资助项目

摘　　要：通过对青藏高原东部若尔盖盆地兴措湖 5 0年来Gyraulussibirica壳体元素及同位素分析 ,并与器测气象资料的比较 ,建立了兴措湖记录与对应的降水和气温间的函数关系 ,探讨了湖泊记录所指示的气候环境意义 .结果表明 :青藏高原东部兴措湖地区腹足类生物在夏半年形成壳体 ,它所记录的是夏半年而不是全年的气候环境信息 ;Gyraulussibiria壳体Mg/Ca比及δ18O指标与夏半年气温有一定的相关性 ,其中壳体δ18O指标对气温变化更敏感 ,δ18O与夏半年气温滑动平均间的变率为 1.64‰ /℃ ,均值比为 0 .2 8‰ /℃ ;Sr/Ca比、δ13 C指标与夏半年的降水量关系较密切 ,尤其是Sr/Ca比随降水量波动呈显著相关变化 ,Sr/Ca变化与降水间的平均变率 (d (Sr/Ca) /dP)为 - 0 .0 4 5 /mm .Here we displayed the results of trace elements and stable isotope in shell Gyraulus sibirica continuously preserved in the sediments of Xincuo Lake, Eastern Tibetan Plateau, in the past 50 years. By coupling these indexs and instrumental meteorological data in its basin, we probed quantitatively modern climatic signals recorded in these indexes to build relative function relations. The results showed that gastropod shells in Xincuo Lake were formed in summer half year, so that trace elements, stable isotope in shells just recorded the climatic signals of the summer half year instead of those of the whole year, Mg/Ca ratio and δ 18O proxy had a certain correlativity with summer half year air temperature, in which δ 18O proxy was more sensitive with variability of δ 18O to temperature d δ 18O/dT 1 64‰/℃; As to Sr/Ca ratio and δ 13C proxy, especially Sr/Ca ratio, there had a close correlation with summer half year precipitation, in which the variability of Sr/Ca to precipitation d (Sr/Ca)/dP is -0.045/mm.

关 键 词：青藏高原 兴措湖 微量元素 同位素 气候信息 生物壳体 碳 氧 铅 铯 

分 类 号：P532[天文地球—古生物学与地层学]